The track density on data storage disks continues to increase. Typically these tracks are circular and are concentrically disposed on a data storage disk of a disk drive. Data may be stored within these tracks via a read/write head of the disk drive. One type of disk drive mounts the read/write head on a slider that flies on what is commonly referred to as an air bearing. This air bearing is a thin boundary layer of air that is carried by the rotating data storage disk. The surface of the slider that projects toward its corresponding data storage disk is configured with one or more air bearing surfaces that compress this boundary layer of air. Compression of the boundary layer of air exerts increased pressure on the slider that results in a sufficient resultant lifting force on the slider, that in turn allows it to remain in vertically spaced relation to its corresponding data storage disk during its rotation.
It is generally desirable to reduce the fly height of the slider above its corresponding data storage disk to improve the signal transfer between the head and this data storage disk. This is becoming more important as the track density on the data storage disks continues to increase (e.g., to make sure the head is communicating with the desired/required track). There are many factors to consider in relation to designing the air bearing surfaces on the slider, or more generally the design of the disk drive. For instance, the linear velocity component of the boundary layer of air on the disk obviously increases as the distance from the disk's center of rotation increases. It is desirable for the fly height of the slider to remain within a certain tolerance, regardless of its radial position relative to its corresponding disk. Another consideration is that the part of the slider that carries the head will typically increase in temperature during read/write operations. This may cause this portion of the slider to expand or protrude toward the corresponding disk, i.e. to undergo pole tip protrusion. Pole tip protrusion typically has an adverse affect on one or more flight characteristics of the slider, including typically a reduction in the fly height of the slider. If the fly height for the slider is designed to be sufficiently “low,” pole tip protrusion may cause undesired contact with the corresponding data storage disk. It would be desirable to have a slider design that compensated for pole tip protrusion during read/write operations in a manner that did not significantly adversely affect the fly height of the slider.